let arr = [1, 2, 3, 4, 5];
let key = {};
let target = 7;
for (let i = 0; i < arr.length; i++) {
  let diff = target - arr[i];
  if (key[diff]) {
    console.log(key[diff], i);
    break;
  }
  key[arr[i]] = i;
}

const obj = {
  name: "coderqian",
};
const obj1 = 1;
obj.hobby = "like";
console.log(obj);
